PROJECT SUMMARY Knee osteoarthritis (KOA) is one of the most prevalent and disabling conditions among veterans and accounts for high morbidity and high costs for the VA. Importantly, chronic reductions in physical activity in patients with KOA may worsen pain, physical function, and exacerbate the metabolic consequences of obesity. The current proposal aims to derive preliminary data to support a large pragmatic trial to address two important knowledge gaps in the management of KOA in order to improve pain and function. Promoting physical activity has been shown to be helpful in reducing pain and improving function in KOA. Our group has shown that social incentives derived from concepts from the field of behavioral economics to promote behavioral change and increase physical activity can be both practical and effective in other settings. The efficacy and safety of incentivizing physical activity using these approaches has not been studied in patients with KOA. Furthermore, whether adjunct therapies such as corticosteroid injections may be a helpful to promote physical activity is unknown and is an additional knowledge gap addressed by the current proposal. Despite widespread use, definitive data quantifying the benefit, if any, of corticosteroid injections are lacking. A large randomized trial tested the effects of corticosteroids injections every 3 months for a period of 2 years on patient reported pain. This study demonstrated no improvement in pain compared to saline and a small decline in cartilage thickness on MRI in the corticosteroid group. These data might suggest that corticosteroid injections result in more harm than good, however, there are critical weaknesses to this study including that pain and function were only assessed at 3-month intervals, while previous trials have suggested that peak benefit is expected at 4-8 weeks. We propose to fill these important Uknowledge gapsU with an innovative and efficient pragmatic study. This double-blinded randomized clinical trial using a factorial and crossover design will leverage unique resources available through the Penn Center for Innovation to capture important patient-reported outcomes in real-time in 32 participants. We will randomize participants to receive social incentives with gamification to promote increases in physical activity. Each patient will also receive both corticosteroids and saline in random order. We will utilize innovative mobile applications for smart phones and wearable activity trackers through the Way-to-HealthPTMP platform and assess, in real time, the impact of the interventions on patient-reported function and pain as well as physical activity. The technology will allow for the recording of outcomes as they occur, thereby avoiding information bias due to poor recall. The study will determine the benefit of social incentivization to promote increases in physical activity in patients with KOA and to determine the efficacy of corticosteroid injections for improving function, increasing physical activity, and reducing pain. Results from the proposed study will provide preliminary data to power a large, feasible, and low-cost pragmatic multi-site trial.